Antiknock control system



H. M. TRIMBLE ET AL 2,315,382

ANTI-KNOCK CONTROL SYSTEM 4 Filed Sept. 5, 1941 INVENTOR HAROLD M. TRIMBLE BY RHEA R. COUCH 24@ WKM/ ATT NEY April 6, 1943.

Patented Apr. 6, 1943 ANTIKNOCK CONTROL SYSTEM narnia M. 'nimble ana Rhea n. couch, Bartlesville, Okla., assignors to Phillips Petroleum Company, a corporation of Delaware Application september s, 1941, serial No. 409,426

9 Claims.

This invention relates to a fuel induction method and apparatus for utilizing condensates having a wide boiling range as motor fuel.

Carbureting systems have been recently developed adapted for handling hydrocarbon fuel ol' relatively high vapor pressure where Athe fuel is introduced into the manifold in both a liquid and a gaseous phase. A difculty encountered in the operation of such systems is a tendency of the engine to detonate during acceleration, or while the engine is under heavy load. The present invention provides an arrangement designed to overcome detonating tendencies of the engine under these conditions and in a novel manner increases the ratio of high octane gaseous hydrocarbon to the liquid fraction in the manifold during such periods when knocking would ordinarily occur. The invention also includes means for adjusting the liquid to gaseous phase ratio following a prolonged period during which an increased quantity of gaseous phase has been utilized.

The present invention is particularly adapted to the use of high pressure fuels such as 26 or 40 pounds per square inch Reid Vapor pressure natural gasoline or any other fuel which may contain a mixture of hydrocarbons which separate into gaseous and liquid phases at normal temperatures and pressures. In fuels of the aforementioned type the gaseous phase ordi-.

narily contains a preponderance of propane, butane, or mixtures thereof which are known to possess high anti-knock value. The gasoline is ordinarily stored under pressure in tanks so that the lighter normally gaseous constituents are liquefied and in admixture with the relatively heavier and normally liquid constituents.

The primary object of our invention is to provide a fuel induction method and apparatus for utilizing wide boiling range condensates as motor fuel.

v-Another object of our invention is to provide an induction method and apparatus for a variety of fuels including natural gasoline, butane, and the like.

A further object is to provide a fuel induction method and apparatus for either a gaseous fuel, a liquid fuel, or any mixture thereof.

Another object of our invention is to provide a fuel induction method and apparatus for reducing the tendency of knocking in internal combustion engines.

These and additional objects and advantages will be apparent to persons skilled in the art by reference to the following description and an- Yillustrating our apparatus.

nexed drawing in which Figure 1 is an elevation view, partly in cross-section, diagrammatically, Figure 3 is a detail of the rack and pinion arrangement employed in Figure 1, while Figure 2 is a section taken on the line A-A of Figure 3.

Referring to the drawing, the numeral 2 desig-- nates a fuel tank remote from the engine, connected by a conduit 3 to a tank l0 which may be a vaporizer or any type of container having asupply of motor fuel constituting a regulator and source of fuel supply. 'A pressure regulator 4 is provided in the conduit 3 in case high pressure fuels are employed, adjusted to deliver a pressure of about 2 pounds per square inch above atmospheric to the container I0. A jacket 5 connected to the engine circulating system by conduits 6 and 1 aids vaporization of the normally gaseous phase in the container I0, the temperature of which is carefully controlled by a thermostat 8 and thermostatic valve 9. A vapor conduit Il, equipped with a zero pressure regulator IIA, connects the container with a gas-air mixer l2 which contains a venturi l3,.and which is flanged at i4 to a two-armed mixing chamber I5. Container I0 is also connected to a -liquid feed carburetor I6 in one arm of the mixing chamber by a conduit I1. Carburetor I6, which contains a venturi I8, is suitably installed relative to the gas-air mixer l2 and is flanged at I9 to twoarmed mixing chamber l5. Mixing chamber l5, which communicates with an intake manifold 20, is provided with a throttle plate 2|, which is operated in a manner well known to the art. Gas-air mixer l2 and carburetor I6 are provided with butteriiy valves 22 and 23, respectively,

which are mounted at right angles to each other on a common shaft 24. Shaft 24 is connected at the right to a hollow shaft extension 25, having a radial slot 26. Extension 25 accommodates a second shaft 21, which is rotatable therein with limits allowed by a pin 28, which is provided on shaft 21, and which is movable in slot 26. It will be noted that container I0 has a float 29, which is connected to a rack 30 by a system of levers f and links generally designated by reference numeral 3|. Rack 30 engages with a pinion 32 -which is secured to shaft 21, causing the shaft to turn whenever the level of the uid in container I0 varies, thus changing the relative position of the butteriy valve and the relative ow of liquid and gaseous phases to the mixing chamber. A diaphragm housing 33 has a diaphragm plate 34, a chamber 35, which is formed in the housing above ,plate 34, and a spring 36 of any desired strength which is centrally positioned on the upper face of plate 34. A conduit 31 oommunicates intake manifold 20 with chamber 35. Spring 36 is employed .to maintain diaphragm plate 34 in a predetermined position during normal operating conditions when a subatmospheric pressure, hereinafter referred to as a vacuum, exists in the intake manifold. An adjusting screw 38 is preferably provided in housing 33 in order to adjust the spring for various operating conditions. It will be noted that diaphragm plate 34 is also connected to a second system of levers and links 39 which connect with a rack 40. Rack 40 engages with a pinion 4|, which is secured to shaft extension 25.

For internal combustion engines adapted to operate with very high compression ratios, it may be desired to add knockpreventing fluids yto the vapor fuel. This may be accomplished by incorporating a device, such as disclosed in United States Patent No. 2,145,156, in butterfly valve 22.

In operation, the fuel induced into the intake manifold 20 is either liquid, vapor, or a combination of liquid and vapor, as desired. Liquid fuel flows from container I through conduit I1 to carburetor I6, and vapor fuel flows from container Y I 0 through conduit Il to gas-air mixer I2. The

proportion of vapor fuel to liquid fuel induced into the intake manifold is controlled by the relative opening of butterfly valves 22 and 23. Our apparatus is adjusted so that the fuel induced into the manifold is primarily liquid under normal operating conditions of the internal combustion engine and primarily gaseous during acceleration or hill climbing. 'Ihe preponderance of the phase, however, depends to a great extent on the constitution of the fuel. The proportion of vapor fuel to liquid fuel varies with changes in height of the liquid level in container Ill, as float 29 acting through lever-link system 3l actuates rack 30, which is in engagement with pinion 32, causing butterfly valves 22 and 23 to open and close. For example, if the liquid level falls, float 29 causes rack 30 to move downwardly, rotating pinion 32, shaft 21, shaft extension 25, shaft 24, and butterfly valves 22 and 23 in a clockwise direction, increasing the amount of vapor fuel inducted to the mixing chamber and decreasing the amount of liquid fuel. It will be noted that during this time pin 28 is in contact with the upper end of slot 26. On the other hand, if the liquid rises in container I0, float 29 causes rack 30 to move upwardly, rotating shaft 21 in a counterclockwise direction, moving pin 28 away from the upper end of slot 26. As this occurs while there is a vacuum in the intake manifold, the vacuum acting through conduit 31 causes plate 34 to 'move upwardly in chamber 35. The movement of the plate is transferred through the link-lever system 39, causing rack to move downwardly and moving pinion 4|, shaft extension 25, and butterfly valve 22 and 23 in a counterclockwise direction until the upper end of slot 26 again makes contact with pin 28, restricting the amount of gaseous fuel to the mixing chamber. Also, when the liquid level in container I0 is constant in height under normal operating conditions, pin 28 contacts the upper end of slot 26, which is important since the throw of pin 28 in slot 26 allows y clockwise movement of shaft extension 25 introducing a preponderance of gaseous phase to the mixing chamber during acceleration when knocking would occur. The vacuum in the intake manirfold acting on plate 34 must produce a torque in extension shaft 25 which is greater than the 75 torque developed in shaft 21 in order to cause butterfly valve 23 to open a greater amount. As the vacuum acting on plate 34 must overcome the action of spring 36, sumcient torque will not be developed and the opening and closing of the butterily valves will be controlled through the liquid level in container lli by float 29. During operating conditions, when there is a pressure rather than a vacuum in the intake manifold, such pressure conditions normally found upon hill climbing, rapid acceleration at slow speeds, and the like, diaphragm plate 34 is urged downwardly, actuating link-lever system 39 to move rack 40 upwardly, rotating shaft extension 25 and shaft 24 in a clockwise direction, causing butterfly valve 22 to more fully open and butterfly valve 23 to more fully close. This increases the amount of vapor fuel being admitted to the intake manifold.

It will be noted that the upper end of Slot 26 moves away from pin 28 until the clockwise rotation is limited by the lower end of slot 26 which contacts pin 28 to prevent further rotation of extension shaft 25 and shaft 24. If this rotation were not limited, all liquid fuel would be shut off from the intake manifold with a resulting rise in liquid level in container I0 and flooding of vapor conduit Il and gas-air mixer I2 with liquid fuel. The pin 28 is again moved into contact with the upper end of the slot 26 as float 29 rises, and the butterfly valves are then relatively moved to admit a preponderance of liquid fuel to the mixing chamber and restore the liquid level to normal. A greater proportion of vapor fuel to liquid fuel is desirable during hill climbing and the like because the vapor fuel has a higher antiknock quality, which gives an improved engine performance when such performance is required.

The liquid level in container Il)l is constant at uniform engine speeds and depends primarily on the constitution of the fuel introduced to the container and the temperature. The relative position of the butterfly valves will then depend on relative proportion of normally liquid and normally gaseous fuel introduced to the container. Fluctuations in engine speed cause the float to rise and fall, regulating the respective flow of liquid and gaseous fuel to the mixing chamber to bring the liquid level to normal. Other regulative means may be employed for this purpose. Y

From the foregoing, itis believed that the operation and advantages of the apparatus for practicing our invention lwill be readily comprehended by persons skilled in the art. Other arrangements may be employed, for instance, a single air inlet for the mixing chamber may replace the dual air inlet. The relative control of liquid and gaseous phases would then be accomplished by a valve arrangement in the liquidv and' gaseous feed lines. Various other changes in the apparatus shown and described may be resorted to without departing from the spirit of the invention, as defined by the appended claims. As an example container l0 may be a double compartment tank for storage of excess vapors or liquid or both.

We claim:

1. In an internal combustion fuel supply system adapted for handling a multi-phase fuel including a normally gaseous phase and a normally liquid phase, fuel air inlets for said liquid and gaseous phases, separate conduits for the liquid and gaseous phases leading to the fuel air inlets, regulative means responsive to the proportional phase to -control the flow of the respective liquid means for increasing the proportional 110W of gaseous phase to liquid phase responsive to pressure increase in the intake manifold.

2. In an internal combustion fuel supply systern adapted for handling a multi-phase fuel including a normally gaseous phase and a normally liquid phase, fuel air inlets for said liquid and gaseous phases, separate conduits for the liquid and gaseous phases leading to the fuel air inlets, regulative means responsive to the proportional supply of the liquid phase relative to the gaseous phase to control the flow of the respective liquid and gaseous phases to the fuel air inlets, and means for increasing the proportion of flow of gaseous phase to liquid phase responsive to pressure increasein the intake manifold.

3. In an internal combustion fuel supply system adapted for handling a multi-phase fuel including a normally gaseous phase and a normally liquid phase, fuel air inlets for said liquid and gaseous phases, separate conduits for the liquid and gaseous phases leading to the mix-ing chamber, valve means in each of said conduits interconnected and coacting inversely Vto control the flow of the respective phases to the fuel air inlets, regulative means responsive to the proportion of supply of the liquid phase relative to the gaseous phase to control said valve means, and means Afor increasing the proportional flow of gaseous phase to liquid phase to the fuel air inlets responsive to pressure lincrease in the intake manifold.

4. In an internal combustion engine fuel supply system vadapted for handling a multi-phase fuel including a normally gaseous phase and a normally liquid phase, fuel air inlets for said liquid and gaseous phases, separate conduits for the liquid and gaseous phases leading to the fuel air inlets, and valve means for increasing the proportion of flow of gaseous phase to liquid phase to the fuel air inlets responsive to pressure increase in the intake manifold.

5. An internal combustion engine fuel supply system for handling a multi-phase fuel including a normally gaseous phase and a normally liquid phase, comprising means for separating said fuel into liquid and gaseous phases, passages for the separated respective phases, each communicating with a fuel air inlet to the engine, valve means proportioning the relative flow of the respective phases through said passages,

` meansv responsive to a change between the rate of separation and the rate of consumption of the respective phases operatively connected with said valve means, and means connected with said valve means responsive to manifold pressure to increase the :dow of gaseous phase.

6. An internal combustion engine fuel supply system for handling a multi-phase fuel including a normally gaseous phase and a normally4 liquid phase, comprising means for separating said fuel into liquid and gaseous phases, means for proportioning the overall flow of the respective phases to correspond with their rate of separation, and means adapted to increase the iiow of gaseous phase in response to an increase in manifold pressure.

7. An internal combustion engine fuel supply system for handling a multi-phase fuel including a normally gaseous phase and a normally liquid phase comprising means for separating said fuel into liquid and gaseous phases, a gas carburetor and a liquid carburetor for the respective phases connected with the engine, valve means for proportioning the relative flow of the respective phasesto correspond with their rate of separation, and means responsive to pressure increase in the intake manifold connected with said valve y means.

8. An internal combustion engine fuel supply system for handling a multi-phase fuel including a normallygaseous phase and a. normally liquid phase comprising means for separating said fuel into liquid and gaseous phases, a gas carburetor and a liquid carburetor for the respective phases connected with the engine, valves for each of said carburetors mounted at an angle to each other on a common shaft, the position of said shaft being controlled by a variation in the rate of separation of the phases, and means responsive to pressure increase in the intake manifold connected with said shaft and adapted to increase the flow of gaseous phase on increase in manifold pressure.

9. An internal combustion engine fuel supply system adapted for simultaneously handling a multi-phase fuel including a; gaseous phase and a liquid phase comprising means for proportioning the relative flow of the respective phases, and means responsive to an increase in pressure in the engine intake manifold to increase the proportion of gaseous phase feed to the engine. l

HAROLD M. TRIMBLE. RHEA R. COUCH. 

